SPOOL GP-CONTROL VALVE 2851504 - Caterpillar

Table 4
Troubleshooting Test Steps    Values    Results    
3. Disconnect the 5 V Sensors, the Voltage Converter, and the Speed Potentiometer while you Monitor the Active Diagnostic Codes
A. Restore the electrical power to the engine. Set the engine control to the STOP position.
B. Monitor the active diagnostic code screen on Cat ET while you disconnect each 5 V sensor at the sensor connector. Disconnect the wiring for the desired speed potentiometer at the potentiometer. Check for an active 3509-3 code or an active 3509-4 code after you disconnect each of the following components:
Wait at least 30 seconds in order for the diagnostic code to become active.
Engine oil pressure sensor
Intake manifold pressure sensor
Temperature sensor at the inlet of the catalytic converter
Temperature sensor at the outlet of the catalytic converter
Speed control potentiometer
C. Set the engine control to the OFF position. Remove the electrical power from the engine.
   
Suspect component    
Result: The diagnostic code deactivates when a particular sensor or the speed potentiometer is disconnected.
Connect the suspect component. If the code returns, replace the component. Connect all of the connectors. Verify that the problem is resolved.
Result: The diagnostic code remains active after all of the 5 V components are disconnected.
There may be a problem in the harness wiring. Leave all of the components disconnected. Proceed to Test Step 4.
   
4. Measure the Voltage of the 5 V Supplies at the ECM
A. Disconnect the J1/P1 and J2/P2 ECM connectors.
B. Fabricate two jumper wires that are long enough to be used to create test circuits at the ECM connector. Crimp connector sockets to one end of each of the jumper wires.
C. Restore the electrical power to the engine. Set the engine control to the STOP position.
D. Use the jumper wires to measure the supply voltage at the ECM. Perform the measurements between the following terminals at the ECM:
Several diagnostic codes that are unrelated to the power supply will become active when the ECM is powered. Disregard these codes while you perform the voltage measurements. If necessary, clear the codes when the test is finished.
J1-41 and J1-34
J1-42 and J2-37
J2-46 and J2-38
J1-48 and J2-40
E. Set the engine control to the OFF/RESET position. Remove the electrical power from the engine.
   
5.0 0.2 VDC    
Result: The voltage measurements are 5.0 0.2 VDC.
The ECM is operating correctly.
There may be a supply wire that is shorted to another wire in the harness. There may be a supply wire that is shorted to engine ground. There may be an open circuit in one of the supply wires that are in the harness. Repair the harness, when possible. Replace the harness, if necessary. Verify that the original problem has been resolved.
Result: The ECM is not generating the correct supply voltage.
There is a problem with the ECM. Perform the following steps:
Temporarily install a new ECM. Refer to Troubleshooting, "ECM - Replace".
If the problem is resolved with the new ECM, install the original ECM and verify that the problem returns. If the new ECM operates correctly and the